But the one theory I read which I really love is that especially in episode 2 is that we are seeing multiple time lines.
And that Ed Harris (The Man in Black) and William (Guest in the white hat) are the same person.
So with William, were seeing his "flashbacks" (or the thirty years prior that MIB refers to)
There are a few hints to support this but you really have to look and pay attention.
And I still say that Mesa Gold the decompression chamber is using the leaving guests in someway to make them or turn them into future hosts.
I'm not sure I go with William and MiB being the same.
I do like the theory that one of them is a flashback
that being the MiB. Maybe the thing that happened 30 years ago was whatever he's up to that we are watching.
Although I can see it the other way too.
I do wonder how someone like William who seems to be a nice ordinary guy would become like the MiB.